Aerobic exercise is a popular form of exercise that improves one's cardiovascular health by reducing blood pressure and providing other benefits to the human body. Aerobic exercise generally involves low intensity physical exertion over a long duration of time. Typically, the human body can adequately supply enough oxygen to meet the body's demands at the intensity levels involved with aerobic exercise. Popular forms of aerobic exercise include running, jogging, swimming, and cycling among others activities. In contrast, anaerobic exercise typically involves high intensity exercises over a short duration of time. Popular forms of anaerobic exercise include strength training and short distance running.
Many choose to perform aerobic exercises indoors, such as in a gym or their home. Often, a user will use an aerobic exercise machine to have an aerobic workout indoors. One type of aerobic exercise machine is a treadmill, which is a machine that has a running deck attached to a support frame. The running deck can support the weight of a person using the machine. The running deck incorporates a conveyor belt that is driven by a motor. A user can run or walk in place on the conveyor belt by running or walking at the conveyor belt's speed. The speed and other operations of the treadmill are generally controlled through a control module that is also attached to the support frame and within a convenient reach of the user. The control module can include a display, buttons for increasing or decreasing a speed of the conveyor belt, controls for adjusting a tilt angle of the running deck, or other controls. Other popular exercise machines that allow a user to perform aerobic exercises indoors include elliptical trainers, rowing machines, stepper machines, and stationary bikes to name a few.
One type of treadmill is disclosed in World Intellectual Property Organization Publication No. WO/1989/07473 issued to Steven T. Sherrard, et al. In this reference, an exercise treadmill includes transverse modular components that are fixably yet slidably supported through T-slots in extruded side rails having inwardly opening T-slots. Landings integral with the side rails cover the edges of the tread belt. The bed is carried on bed rails supported on the side rails by bolts extending through the T-slots into bed slides. Transverse bed supports capped by resilient shock mounts support the center of the bed. Idler and drive rollers at opposite ends of the bed are slidably supported through the T-slots of the side rails on bearing slides. The rear idler roller is adjustably positioned by bolts engaging end caps at the rear ends of the side rails. A motor moves the tread belt over the bed and rollers. An inertial flywheel, fan and encoder wheel are mounted on the motor axle. A linear lift mechanism within the stanchion raises and lowers the treadmill. This reference also indicates that the inertial flywheel is significantly heavier than those found in other exercise treadmills to reduce the peak loads placed on the treadmill's motor. A fan recessed within the outer surface of the flywheel draws air between the spokes of the flywheel and over the air inlet grill of the motor.